There has conventionally been a DVD-RAM as an information recording medium for recording or reproducing real time data such as a video, audio or the like on a disk, one example of which is disclosed in Japanese Patent No. 3171584. This example defines a standard reproduction model shown in FIG. 8A for securing a real time reproduction of data discretely stored on a disk, and sets an access performance model shown in FIG. 8B for providing a relationship between an access distance and access time as the standard reproduction model. The standard reproduction model is formed in order to determine a condition that various types of reproducing apparatuses can continuously reproduce real time data on an optical disk in order to reproduce real time data on the standard reproduction model, a data storage area is set in advance in accordance with the access performance model shown in FIG. 8B so that data in a buffer memory 103 does not underflow during an access and thus the reproduced video or audio is not broken off. The real time data is arranged at the set storage area and then is recorded thereto. As described above, data-recording is performed to the storage area that satisfies the access performance model, such that the real time data can continuously be reproduced according to setting of the standard reproduction model upon the subsequent reproduction.